Using string variable to call a method

[Bryan Richardson]

[Note: parts of this message were removed to make it a legal post.]

Hello all,

How can I use a string variable as part of a method name I'm calling? For
example say I want to call the method say_hello using the following:

def say_hello
puts "Hello!"
end

str = "hello"

say_????

Thanks in advance!! -- BTR

 

[Stefano Crocco]

Alle luned=EC 7 gennaio 2008, Bryan Richardson ha scritto:

Hello all,

How can I use a string variable as part of a method name I'm calling? For
example say I want to call the method say_hello using the following:

def say_hello
puts "Hello!"
end

str =3D "hello"

say_????

Thanks in advance!! -- BTR

send "say_#{str}"

Stefano

 

[Thomas Wieczorek]

You can use: eval, instance_eval, class_eval, module_eval oder send
The different evals are described here:
http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/192513
(click on the "N" to read the next message in the thread)
send is as far as I understand it, used to send messages to objects.
Keep in mind that method calls are messages send to objects.

 

[Daniel Finnie]

[Note: parts of this message were removed to make it a legal post.]

In general, the send method is preferred over evalling a string when
possible.

In addition to send "say_#{str}", you can do method("say_#{str}".to_sym)
call.

Dan

 

[Bryan Richardson]

[Note: parts of this message were removed to make it a legal post.]

Along these same lines, is it possible to do a require and include
dynamically, getting the name of the file to require and module to include
from a string?

 

[Jason Roelofs]

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require is obvious, the method takes a string already.

Including a module, I think you can do:

ClassName.sendinclude, Module.const_get("ModuleName"))

or if you're working with an instance variable, replace :include with
:extend.

Jason

 

[Bryan Richardson]

[Note: parts of this message were removed to make it a legal post.]

send :include, Module.const_get(ARGV[1]) worked. Thanks!!